Here is how I come up with numbers to determine if the dining plan is worth it or not for us, please note the cost per meal is what I would spend on the plan on average per meal, as I will order what I want and not worry about the cost as I would if paying OOP, remember you tend to eat better if on the dining plan and that may make it worth it right there:
TS:
(Number of People x number of nights) x $30 + 7.25% tax (as I recalll that's the tax rate, remember tax is included, gratuity is not)
35 * $30 = $1,050 +$76.13 = $1,126.13
(If paying OOP for all. I would worry more about price and the follwing formula would be used for my actual costs):
35 * $25 = $875 + $63.44 = $938.44
CS:
(Number of People x number of nights) x $12 + 7.25% tax
35 * $12 = $420 + 30.45 = $450.45
(If paying OOP for all):
35 * $10 = $350 + $25.38 = $375.38
Snacks (Note I am only going to use the number snacks that will be able to be used on the dining plan, as either way you will most likely purchase additional snacks):
(Number of People x number of nights) x $3.80 + 7.25% tax
35 * $3.80 = $133 + $9.64 = $142.65
The snac dollar ammount generally reamins the same on or off of the plan.
How much the food that you would actually eat on the plan would cost (remember these are average prices based on personal experience):
$1,126.16 + $450.45 + $142.65 = $1,719.43
Estimated cost if not on the plan and watching the costs (a lot more stressful in my opinion, esp. with that large of a group):
$938.44 + $375.38 + $142.65 = $1,456.47
So saving would be:
(Food you are actually getting on the plan):
$1,719.43 - $1,329.65 = $389.78
(Savings over how much you would likely pay OOP off the plan):
$1,456.47 - $1,329.65 = $126.82
Now, I have not added anything in here, such as the lower stress factor of not having to worry about the cost of the food while in the parks, knowing that your meals are prepaid, so you don't have to worry as much about going over budget while there, etc. In my opinion, it is hard to put a price on such things, but if someone twisted my arm, I would say a mark up of about 15% of the cost of the food would be reasonable, thus making the DDP an even better value. Please note that for averaging things out, I used our low end numbers, some of our meals would have been as much as $60 per person on the dining plan, of course we never would have ordeed that without the plan, but it was good to be able to get what we really wanted.